The objective of the Childrens Cancer Study Group is to develop and test new treatments for the cancers of infants and children in order to improve the cure rate. This application is for the continuation of the program designed to extend effective cancer management and treatment to major community pediatric hospitals and to inform community physicians regarding the proper management of these patients with cancer. The CCSG has conducted this cancer control program for the past 7.5 years under the auspices of contract funding from the NCI. This new application is in response to a request for grants to continue and extend the cooperative group program in cancer control. The CCSG is a multidisciplinary, multimodality, multi-institutional cooperative organization. Its membership includes teams of investigators at 29 of the major pediatric referral medical centers in North America. There are over 1,100 M.D.'s and Ph.D's at those institutions who have specific responsibilities for conducting the scientific activities of the Group. Member institutions, and their affiliated institutions, annually register close to half of the new pediatric cancer patients diagnosed in this country. Over 60% of registered patients are entered on formal clinical studies conducted by the Group. The major areas of research are studies of LEUKEMIA, SOLID TUMORS, NEW AGENTS, and SPECIAL STUDIES, of Immunology, Pathology, Epidemiology, Supportive Care, Late Effects, and Biology. The direction and coordination of group activities in the responsibility of the Group Chairman, assisted by the Administrative Director, the Group Statistician and the staff of the Group Operations Office. Group scientific priorities and policies are implemented by the Group Chairman with the advice and consent of the Group Executive Committee.